Auckland mayoral candidate Viv Beck has pulled out of the race today, abruptly abandoning a bid that has been dogged by questions over campaign finances.

The Heart of the City chief executive is the second big name to quit, following the decision by restaurateur Leo Molloy to bow out on August 12.

Her late withdrawal means her name will remain on voting papers, with postal voting beginning today.

In a statement, Beck said: "My decision comes with a heavy heart but given the strength of concern about issues that need addressing across our region, it is important to avoid splitting the centre-right vote.

"I would like to acknowledge the hard work and unwavering support from my team, in particular the quality work on policies to address Aucklander's concerns.

"I have also been heartened by the support I have received from people keen to see a different style of leadership governing our region and to those people, including C&R, I say a sincere thank you."

‌"I am concerned about gross inaccuracies that have been said about me and my campaign and will be reflecting on the impact this type of behaviour has on democracy.

"Overall, I am grateful to have had the opportunity to speak with so many people over the last few months and to hear their views on what needs to be done if we are to realise our region's full potential.

"I'd like to see our region thrive, with a shared vision for a vibrant, inclusive and sustainable future and I look forward to playing my part in making this a reality."

Campaign plagued by financial claims

Beck's campaign has been plagued with revelations of an unpaid $353,000 bill to an advertising company, taking her focus away from the contest to replace outgoing mayor Phil Goff.

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Her poll ratings have fallen from 21 per cent June to 13 per cent last month, placing her in fourth position behind Labour-endorsed Efeso Collins, businessman and former Far North District mayor Wayne Brown and Molloy.

When the latest poll showed Molloy had dropped from second to third, the self-described "hospo legend" said he could not win and removed his name from the ballot to help a "change" candidate beat Collins.

Beck's decision to pull out on the day postal voting begins could see the change vote can coalesce around Brown, whose self-funded $500,000 campaign has been building momentum over the past month.

Beck stood on a pro-business, centre-right platform with policies of getting tough on crime and dumping the Government's $14.6 billion light rail project for rapid buses alongside the north-western motorway and from Botany to the airport.

The Auckland Council has had two Labour-endorsed mayors since it was formed in 2010 - Len Brown and Phil Goff.

To date, Collins has led the polls, but with support in the mid 20s, he is a long way off the 50 per cent of the vote secured by Brown and Goff at each of their two election victories.